1. Field of the Invention
The present invention relates to an ultrasound observation apparatus, and particularly relates to an ultrasound observation apparatus capable of creating a blood flow image of a subject.
2. Description of the Related Art
An ultrasound observation apparatus has been conventionally used widely, which can obtain a tomographic image of a living body, and a blood flow image of an inside of a region of interest of the tomographic image by transmitting ultrasound into the living body as a subject and receiving reflection wave which is the ultrasound reflected in a biological tissue as an examined region in the living body. Further, the tomographic image and the blood flow image of the living body which are obtained by the aforementioned ultrasound observation apparatus are used, for example, when an operator and the like observe penetration depths of lesions, or observe a state of an inside of an organ. As the apparatus having such a function, there is proposed an ultrasound diagnostic apparatus of, for example, U.S. Pat. No. 6,419,632.
U.S. Pat. No. 6,419,632 discloses a configuration for making it possible to acquire a blood flow image of a microvessel existing in the subject by transmitting an ultrasound pulse having a wide-band frequency characteristic and performing predetermined signal processing for an echo signal which is the ultrasound pulse reflected in the subject, in the ultrasound diagnostic apparatus.